Spectre (Strife)

From DoomWiki.org

Spectres are enemies from Strife. They are mysterious creatures which appear as a cloud with one eye. They possess the bodies of various characters in Strife and bend their will to evil desires, making the possessed people into dangerous maniacs, only bent on searching for the Sigil in order to release their master, the Entity. Spectres attack with Sigil powers and usually drop a Sigil piece when they are killed (an exception is the Programmer's Spectre at an ancient temple). Each Spectre takes a different amount of damage. Spectres can only be hurt with the Sigil.